When using QlikView as the source (Connection) and requiring image output only as the resultant report - for example PNG, GIF, JPEG or BMP files as opposed to PDF, Office or HTML type files, these tips could greatly improve performance:
- Image type reports typically use very few objects or even a single sheet so try to use a single QlikView document as the source. Creating several connections to documents that contain different objects will lead to unnecessary overhead. NPrinting 17.4 will roughly open a qv.exe for each group of 10 requests of the same connection (#qv desktop opened on a connection = Ceiling(#requests of the connection/10)). Opening instances of QlikView takes a significant amount of time, so it is possible that opening several documents could take up more time than retrieving several images from a single document. In any case, opening phases are sequential, not done in parallel, and so this will slow down the general process.
- Avoid reloading documents during scheduled report generation times. The reload of any of the document on the server will cause some requests to fail and to be retried. This would involve opening a new qv.exe instance for the reloaded document version. In general (for larger reports) this prevents certain inbuilt performance optimizations done on requests with the same filter (where "No filter" is a blank/empty filter but a filter nonetheless). As a general rule of thumb we should avoid interruptions caused by data reload as much possible as these will eventually trigger a new report production process nullifying all the work previously done and causing new instances of qv.exe to be opened.
- Avoid PixelPerfect report type if possible as it is the slowest of all report types. For QlikView image rendering consider NPrinting Entity Reports as it is a much faster option.